1. Field of the Invention
This invention concerns a catheter for selective coronary arteriography of a coronary artery. More particularly, it concerns such a catheter which is inserted through an artery in the arm.
2. General Discussion of the Background
Many heart diseases are caused by occlusion of one or more of the coronary arteries that supply oxygen to the heart. The proper diagnosis and treatment of these diseases requires an accurate evaluation of the condition of the coronary arteries. One frequently used technique for making such a diagnosis is coronary arteriography, a procedure in which a catheter is inserted into the aorta of the heart and positioned adjacent or within the ostium of a coronary artery. A radiopaque dye is then injected through the catheter into the coronary artery while an X-ray is taken. The pattern of movement of the dye, which can be detected on a flouroscopic screen, helps provide an assessment of the condition of the artery being examined.
The catheters are inserted into the aorta either through the femoral artery adjacent the groin or through the brachial artery in the arm. The catheters shown in U.S. Pat. Nos 4,033,331, 4,117,836 and Canadian Patent No. 930636 are specifically configured for insertion through the femoral artery. There are several disadvantages, however, to this approach In the first place, femoral catheterization is suffiently traumatic that the patient's leg must remain flat for about four hours after the procedure to avoid bleeding. A secondary problem is that the surge of blood pressure within the femoral artery makes it difficult to control bleeding after the procedure.
Catheterization through the brachial artery in the arm avoids these problems. During the procedure and afterwards, the surge of arterial pressure can be more easily controlled by putting a pressure cuff around the upper arm. Subsequent to brachial catheterization, only about 11/2 hours of rest are required since stresses on the arm are not great when the patient starts walking.
In spite of the advantages of brachial catheterization, there are no catheters which are specifically configured for insertion through the brachial artery for secure placement within the aorta. U.S. Pat. Nos. 3,935,857 and 4,531,936 disclose catheters which can be inserted into an artery in the arm or leg. The '857 catheter, however, is simply a continuous curve having a pair of legs disposed at an angle of about 85.degree.. Such a configuration does not allow the catheter to be securely seated in the aorta with the open end of the catheter inserted into an ostium of the coronary artery which is being catheterized. The catheter is therefore relatively free to move about in the aorta, which can allow the tip to become dislodged from the arterial ostium. This problem can cause serious delays in arteriography which increase the duration of the procedure and the risk of side effects.
It is accordingly an object of this invention to provide a catheter which is specifically configured for insertion through an artery in the arm.
It is another object of the invention to provide such a catheter having an end portion which is shaped to seat firmly within the aorta such that the open tip of the catheter can be easily and securely placed in the ostium of the artery being examined.
It is a further object of the invention to provide such a catheter which is not easily dislodged once in place.
Even yet another object of the invention is to provide such a catheter which can minimize damage to the brachial, axillary and subclavian arteries through which it is inserted.